Froth-flotation concentration of ores



Patented Dec. 14, 1926.

cam. PIERCE Lewis, on Bonn-mama; oauromara, assrenoa '10 iamnnans earn- BATION NORTH AMERICAN CORPORATION,

OF MARYLAND.

OF NEW YORK, N. Y., A CORPORATION FROTH-I'LOTATION CONGENT TION OF ORES.

1T0 Drawing.

This invention relates to the'froth-flotation concentration ofores and is herein illustrated as applied to the concentration of zinc-bearing ores containing iron.

It has been found that zinc ores, whichmay also carry other values such as lead, silver, or copper, can be concentrated so as to yield a zincconcentrate well above merchantable grade at a single operation, and that the 1 zinc concentrate may carry ninety per cent r I Application filed April 19, 1926. Serial No. 103,171.

the pulp agitated to disseminate the, lime. Thls gave the pulp adete'ctable alkalinity. Then there was added in the order named one pound of copper sulphate, 0.15zpounds of steam distilled pine oil, and 0.1 pounds of potassium xanthate, and the agitation and aeration continued while a' zinc-bearing froth was collected for seven minutes. The results are shown in the following table:

Ass or more of the zinc of the ore while most of aw the iron is excluded from that concentrate. wz. Ag. Pb Zn. re

In the examples given below the ore pulpis subjected to the agitation and aeration of Percent Ounce: Per mu Per cent Pu and 1 the froth-flotation process for the flotation 2&2 a; 21?, a: i; of the zinc in the presence of a sulphur-con- Tail as a; -1.; 5 taining organic compound such as a xanthate which is added to the ore pulp after'sufii- Recwmem cient lime has been added'to give the pulp 20 an alkalinity which may be just detectable ."-An- Pb. Zn re by phenolphthalein. 7 Some -of the other metalliferous minerals present may be floated 183 5 333 333 6 g first, if desired. The xanthate which is here- 7 ads J a'o 21s, in disclosed as a salt of xanthlc acid, or part T i; &2 $13. of the required xanthate, may be added for 5 =4 the flotation of these other minerals. In This procedure has been found effective such case the lime is usually added after in concentratin the refractory cop er-z'inc' they have been floatedfland then there is ores of the A terthought and Bul y Hill I usually added a small quantity of a cop er mines, yielding a concentrate assaying 54% 3o salt, such as copper sulphate, and a fart er of zinc with a zinc recovery of 88%. I

quantity of xanthate, and any desired or nec- The process has proved effective in obtain-. essary mineralfrothing agent 'or agents. ing a richer zinc concentrate relatively lower This procedure has been found extremely in iron than has hitherte been obtained from effective in separating lead and zinc, as is a refractory zinc ore (carrying iron and cop: :55 illustrated in a test of a silver-bearing leadper) from Gunnison county, Colorado.- A zinc ore from the United Mines Company of pulp of the suitably ground orewas agitated British Columbia. The suitably ground Ore in the same machine with limeequivalentto was made into a pulp with water and agi 5 pounds of calcium oxide, 1 pound of (10 ta'ted for seven minutes in a minerals separaperv sulphate, 0.15 pounds of potassium xan- -10 tion spitzkast'en subaeration testing machine thate, 0.1 pounds of steam-distilled pine oil,

with 0.12 pound of otassium xanthate, and 0.1 pound of cresyhc acid, both per ton of ore, and a lead-bearing froth was collected. Then there was added lime equivalent to 4 pounds of calcium oxide per ton of ore and and 0.2 pounds of water gas tar, all per ton of ore, and a rougher froth concentrate col-. lected for fifteen minutes. This rougher con centrate was reagitated without any addition of reagents for five minutes to yield a fin per ton of potassium xanthate,

zinc-bearing froth 'of the iron.

iron-bearing Z1110 ished concentrate and. a middling. The final" results are shown in the following table:

" minutes.

alent to 5 pounds of calcium oxide, one

pound of sulphate of copper, 0.1 pounds of steam distilled pine oil, 0.2-pounds of water gas tar, all per ton of ore, and a rougher froth concentrate was collected for fifteen This rougher'concentra-te Was reagitated to separate it into a finished concentrate and a middling without the addition of any further agents. The results are A pulp of suitably ground Silver King Coalition silver-bearing lead-zinc ore was agitated in the same machine with 0.15 pounds of potassium xanthate, 0.15 pounds of cresy'lic acid, 0.15 pounds of a mixture of naphthalene and'xylene, all per ton 'of ore, and then durin further agitation there was added 0.3 pounds of sodium cyanide per ton of ore, and a lead-bearing froth concentrate collected during ten minutes agitation. To the remainder of the pulp was added lime equivalent to 6 pounds of calcium oxide, 1 pound of sulphate of copper, steam distilled pine oil, 0.05 pounds of potassium xanthate, all per ton of ore, and a concentrate collected during ten minutes agitation. To the remainder of the pulp was then added 1.5 pounds of sodium silicate, and 0.1 und of cresylic acid, both per ton of orlginal ore, and a silver-bearing froth concentrate collectedfor seven minutes. All three concentrates were of commercial ade. The lead concentrate was very rich in lead and carried most of the silver, the zinc concentrate was well above the minimumzinc content required by the smelters, and the. silver concentrate was commercially valuable for its silver content although it carried most of the iron. The results are shown in detail in the following table:

Assays.

Wt. Ag. Pb. Zn. Fe.

Per cent Ounces Per cent 'Per cent Per cent 100. 0 47. 61 29. 1 15. 2 6. 7 41. 2 6' 67.6 8.0 1. 8 1S. 9 33. 2 2. 7 60. 0 2. 2 11. 8 17. 0 5.0 4. 0 36.0 28.1 4.2 1.0 .2 4.5

Recoveries.

1! Ag. Pb. Zn. Fe.

. Per cent Per cent Per cent Per cent Heads.. 100. 0 100.0 100. 0 100. 0 80. 1 95. 3 2i. 5 ll. 1 13. 2 1. 7 75.0 6. 2 4. 2 2. 0 3. 1 63. S 2. 5 1. 0 .4 18. 9

Sometimes the recovery of zinc has been extraordinarily high witha lar e rejection A pulp of suitafily ground ore from Virginia was agitated in the same machine with 0.1 pounds lime 'equiv-.

0.1 pound of froth.

shown in the following table Assays Recoveries vWt. Zn. Fe. Zn. Fe. Per cent Per cenl Pcr cent Per cc nt ler can! 100. 0 22. 5 6. 0 100. 0 100.0 30. 6 56. 4 2. 6 92. 0 l6. 0 6.15 14. 6 12. 2 4. 3 l3. 6 '56. 8 1. 5 7. 4 3. 7 70. 4

Having thus described certain embodiments of my invention what I claim is:

1. The process of concentrating an ironbearing zinc ore which consists in agitating a .pulp of the ore with suflicien't lime to render it alkaline and with a sulphur-containing organic compound, further agitating it with a copper salt and with a mineralfrothing agent to produce a mineral-bearing froth relatively rich in zinc and poor in iron, and separating the froth.

2. The process of concentrating an ironbearing zinc ore which consists in agitating a pulp of the ore with suflicient lime to render it alkaline and with xant-hate, further agitating it with'a copper salt and with a mineral-frothing agent to produce a mineral-bearing froth relatively rich in zinc and poor in iron, and separating the froth.

3. The process of concentrating an iron- 1 bearing zinc ore. also carrying another value which consists in agitating a pulp of the ore with a sulphur-containing org'anic comadding sufiicient lime to render the pulp de- 3 also adding a copper salt and another agent, agitating the pulp to tectably alkaline,

pro uce a mineraLbearingfroth relatively rich in zinc and poor in iron, and separating the froth.

4. The process of concentrating an ironbearing zinc ore also carrying another value 'whichconsists in agitating .a pulp of the ore with agents to cause it to .produce a mineral-bearing froth relatively rich in the other value, separating the frotl'i, adding sufiicient lime to render the pulp 'cdetectably alkaline, also adding ,a copper salt and a sulphur-containing organiccompound and another agent,; agitating the pulpto produce a mineral-bearing froth relativelyrich 1n zinc and poor in iron, and separating the 5. The process of concentrating an ironore'with xanthate and another agent to cause it to produce a mineral-bearing froth relatively rich in the other value, separating the froth, adding suflicient lime to render the pulp detectably alkaline, also adding a cop- 'per salt and further xanthate and another agent, agitating the pulp to roduce a mineral-bearing froth relatively rich in zinc, and

separating the froth.

6. The process of concentrating an ironbearing zlnc ore also carrying silver and lead, which consists in agitating a pulp of the ore with a sulphur-containing organic compound and another agent to cause it to produce a mineral-bearing froth relatively mineral-bearing frot relatively rlch in' zinc and poor in iron, separatlng the'froth, add-' rich in lead and poor in iron, separating the froth, addin suflicient lime to render the pulp detecta ly alkaline, adding acopper salt, adding further sulphur-containing organic compound, 'tatlng to roduce a ing further agent, agitating to produce a mineral-bearing froth relatively rlch in silver anddron, and separating the froth.

7. The process of concentrating an ironbearing zinc ore also carrying silver andlead which consists in agitating a pulp of-the ore with xanthate and another agent to cause it to produce a mineral-bearing froth relatively rich in lead and poor in iron, separat- -ing the froth, addin sufiicient lime to render the pulp detecta ly alkaline, adding a copper salt, adding further xanthate, agitating to produce a mineral-bearing froth relatively rich in zinc and poor in iron, separating the froth, adding ther agent, agitating to produce a m' eral-bearing froth relatively rich in silver and iron, and separating the froth.

8. The process of concentrat ng a zinc ore containing also another value which consist in agitating a pulp of the ore with a sulphur-containing organlc compound and with a 'mineral-frothlng agent to produce a mineral-bearing froth relatively rich'in said other value separating the'froth, adding sufficient lime to render the pulp alkaline and another suitable agent, further agitating thepulp to' causeit to yield a mineral-bearing froth relatively rich in zinc, and. separating the froth. j

9. The process of concentrating a zinc ore containing also another value which consists in "agitating a pulp of the ore with xanthate and with a mineral-frothing agent to produce a mineraI bearing froth relatively rich in said other value, separating the a mineral-bearingfrotlr relatively duce a mineral-bearing. froth relatively rich froth, adding suflicient lime to render the bearing zinc ore also carrying another value which consists in agitatlnga pulp of the pulp alkaline and another suitable agent, further agitating the pulp to cause it to yield rich] in zinc, and separating the froth.

-. 10. The process of concentrating a ore containing also another valuewhich' consists in agitating a pulp of the ore with a sulphur-containing organic compound and a mineral-bearing froth relatively richin jwith a mineral-frothing agent to produce the other value, separating the froth add-j ing sufiicientolime to render the pulp detectably alkaline, adding a copper salt and further sulphur-containing. organic compound, further agitating to produce a mineral-bearing froth. relatively rich in zinc,

,and'separating the froth. r

11. The process of concentrating a 'zinc ore containing also another value which consists in agitating a pulp of the -ore with xanthate and with a mineral-frothing' agent to produce a mineral-bearing froth-relatively rich in the other value, separating the froth,

adding suflicient lime to render the pulp detectably alkaline, adding avcopper-salt andfurther Xanthate, further agitating to proin zinc, and separating the froth.

, 12. The process of concentrating a zinc ore also carrying silver and lead which consists in agitatlng a pulp of the ore with a sulphurcontaining organic compound and an agent to cause it to. produce a mineral-bearing froth relatively rich in lead, separating the froth, adding. sufficient lime to renderthe pulp detectably alkaline, adding ,a copper salt, adding further sulphur-containing organic compound, agitating to produce a' mineral-bearing froth relatively rich 'in zinc, separating the froth, adding further agent, agitating to produce'a mineral-bearing" froth relatively rich in Sil"8r,"a11d ge rating the froth. a

13.- The'process of concentrating a zinc ore also carrying" silver and lead which consists in agitating a pulp of the ore'with arenthate'and an agent to cause'it to produce a mineral bearing froth relatively rich in lead, separating the. froth, adding suflicient lime to render the pulp detectably alkaline, adding a copper salt, adding further xanthate, agitating to produce a mineral-bearing froth relatively rich in zinc, separating the froth, adding further agent, agitating to produce a mineral-bearing froth relatively rich in silver, and separating the froth.

In testimony whereof, I have afiixed my signature to this specification.

' CARL PIERCE Laws.

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